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Primary brain tumors, those that originate in the brain, are more frequent in children and older adults. One feature that sets brain tumors apart from those arising from other tissues in the body is their inability to exit the brain to form secondary, or metastatic, tumors in other organs. They do, however, have a tendency to invade the surrounding brain to establish new tumors within the cranium. The most serious type of intrinsic brain tumor is called glioblastoma multiforme, or GBM.
In men and women less than 20 years old, brain cancer is, after leukemia, the next most prevalent cause of cancer deaths. Apart from leukemia, intracranial-derived tumors are the next leading cause of fatality in men between the ages of 20 and 30. In females between 20 and 39 years old, brain tumors are the fifth most prevalent cause of cancer deaths.
Luckily, GBM is infrequent; there are no more than two or three new cases per 100,000 individuals and account for only 20% of all intracranial neoplasms. Their propensity to invade the surrounding brain tissue means that it is not possible for them to be completely eradicated by surgical means. Try scraping off every bit of butter from a slice of toast.
The type of cell that gives rise to GBM is the glial cell, of which there are three types. Nerve cells lose their ability to divide once they have reached terminal differentiation. Glial cells, on the other hand, are able to divide throughout the life of the individual. Evidence from both in vivo studies in the '60s and in vitro studies in the '90s and early 21st century support the hypothesis that most, if not all, intrinsic brain tumors begin forming in the developing fetus.
Glial cells come in three different forms: microglia, astrocytes and oligodendrocytes. Of these, astrocytes and astrocytic tumors, are the most common. The nastiest, most malignant and most deadly variant of astrocytoma is the GBM, which has a median time of survival without treatment of less than five months.
Astrocytes are star-shaped glial cells found in the brain and spinal cord. The provide support to the endothelial cells that form the blood brain barrier, provide nutrients to nervous tissue and form a part of the repair process following trauma to the central nervous system. There is evidence to suggest that astrocytes communicate with nerve cells by releasing a neurotransmitter called glutamate.
Oligodendrocytes are less spiny than their astrocytic cousins. Their main role in the nervous system is to provide a fatty sheath of insulation that makes more rapid nerve transmission possible. One oligodendrocyte can ensheath up to 50 neurons. The fatty sheath, called myelin, comes under attack from immune system cells in the debilitating condition known as multiple sclerosis (MS).
Microglia are the smallest members of the glial cell team. Their main function is to provide a rapid response to invading foreign bodies and prepare them for slaughter by T-cells. They do this by engulfing foreign matter in a process called phagocytosis. Resting microglia are the prettiest, and look like tiny astrocytes. Activated microglial cells look more bulbous with the processes less prominent.
In men and women less than 20 years old, brain cancer is, after leukemia, the next most prevalent cause of cancer deaths. Apart from leukemia, intracranial-derived tumors are the next leading cause of fatality in men between the ages of 20 and 30. In females between 20 and 39 years old, brain tumors are the fifth most prevalent cause of cancer deaths.
Luckily, GBM is infrequent; there are no more than two or three new cases per 100,000 individuals and account for only 20% of all intracranial neoplasms. Their propensity to invade the surrounding brain tissue means that it is not possible for them to be completely eradicated by surgical means. Try scraping off every bit of butter from a slice of toast.
The type of cell that gives rise to GBM is the glial cell, of which there are three types. Nerve cells lose their ability to divide once they have reached terminal differentiation. Glial cells, on the other hand, are able to divide throughout the life of the individual. Evidence from both in vivo studies in the '60s and in vitro studies in the '90s and early 21st century support the hypothesis that most, if not all, intrinsic brain tumors begin forming in the developing fetus.
Glial cells come in three different forms: microglia, astrocytes and oligodendrocytes. Of these, astrocytes and astrocytic tumors, are the most common. The nastiest, most malignant and most deadly variant of astrocytoma is the GBM, which has a median time of survival without treatment of less than five months.
Astrocytes are star-shaped glial cells found in the brain and spinal cord. The provide support to the endothelial cells that form the blood brain barrier, provide nutrients to nervous tissue and form a part of the repair process following trauma to the central nervous system. There is evidence to suggest that astrocytes communicate with nerve cells by releasing a neurotransmitter called glutamate.
Oligodendrocytes are less spiny than their astrocytic cousins. Their main role in the nervous system is to provide a fatty sheath of insulation that makes more rapid nerve transmission possible. One oligodendrocyte can ensheath up to 50 neurons. The fatty sheath, called myelin, comes under attack from immune system cells in the debilitating condition known as multiple sclerosis (MS).
Microglia are the smallest members of the glial cell team. Their main function is to provide a rapid response to invading foreign bodies and prepare them for slaughter by T-cells. They do this by engulfing foreign matter in a process called phagocytosis. Resting microglia are the prettiest, and look like tiny astrocytes. Activated microglial cells look more bulbous with the processes less prominent.
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